N Surendran pointed out that deputy home minister Shamsul Anuar Nasarah had said Malaysian police interviewed Pannir for about four hours at Changi prison in Singapore on Sept 27.

During the interview, held 11 days before his execution, Pannir was asked to identify other suspects linked to the drug trafficking trade through photographs.

“How is it possible that in less than 10 days the police had concluded that there was no value in the information given?” Surendran said in a statement today.

“How could the police have carried out a thorough and proper probe in a matter involving complex cross-border criminal activity and suspects still at large in just 11 days? Why the extreme haste in closing the investigations?”

Surendran labelled the dismissal of Pannir’s information as “the final nail in Pannir’s coffin” since it had thrown out any possibility of halting the Malaysian’s execution on Oct 8.

He said Pannir had submitted an application to stay the execution based on the assistance he had rendered to Malaysian police to bust cross-border drug syndicates.

Singapore’s central narcotics bureau had also cited the deputy minister’s remarks in Parliament in its press statement confirming Pannir’s death.

The day before Pannir’s execution, Shamsul said no new investigation was launched despite police interviewing the Malaysian inmate as information he had provided held “no operational value for the police to conduct further investigations”.

He said police had earlier investigated three people named by Pannir and his family, but found no criminal links.

Shamsul also said Singapore’s courts had found drugs taped to Pannir’s leg and hidden in his motorcycle, showing that he was not just a courier.

Surendran disputed this and accused Shamsul of misleading the Dewan Rakyat, saying the Singaporean court had, in fact, ruled that “Pannir was a mere courier” in its judgment.

“This is tantamount to misleading Parliament and the public. No retraction or explanation has so far been given by the government. If the government got such a basic fact wrong in its parliamentary statement, what else did it get wrong?” he said.

Pannir was executed on Wednesday for smuggling 51.84g of diamorphine into Singapore in 2014. He was the second Malaysian to be put to death for a drug offence in the city-state in two weeks, after the execution of K Datchinamurthy, 39, on Sept 25.